Evidence on long term outcomes of opioid substitution therapy is limited, but suggests a generally poor outlook for heroin addicts who seek any form of treatment. One consequence of this trap of low expectations (therapeutic nihilism), the failure by discouraged staff to foster the possibility of good outcomes, and for treatment to descend to the mechanical issuing of opioid prescriptions. Low expectations may also foster cynical, profit-oriented treatment.

In any area of health care, where outcomes are poor there are always people keen to market optimism. (There has always been a thriving market for alternative therapies in areas such as cancer and serious neurological disease where treatment options are limited.) Therefore the trap of low expectations is episodically interrupted by people who assert that there is room for optimism, that outcomes can be better even if there is not yet evidence to support this. Optimism about addiction is what patients, their families and politicians want to hear. This, by contrast, can lead to the trap of high expectations that can also be self-defeating, promoting resistance and setting patients up for failure. The ethical challenge in treating heroin (and other forms of) addiction is in finding a balance between excessively low and excessively high expectations in clinical practice and in policy.